package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.USER_FOLLOW_KEY;


@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取登录的用户
        UserDTO user = UserHolder.getUser();
        if (Objects.isNull(user)) {
            return Result.fail("当前尚未登录");
        }
        Long userId = user.getId();
        //关注还是取关
        if (isFollow) {
            //关注，新增数据
            Follow follow = new Follow();
            follow.setFollowUserId(followUserId);
            follow.setUserId(userId);
            boolean save = save(follow);
            if (save) {
                stringRedisTemplate.opsForSet().add(USER_FOLLOW_KEY + userId, followUserId.toString());
            }
        } else {
            //取关，删除数据
            boolean remove = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));
            if (remove) {
                stringRedisTemplate.opsForSet().remove(USER_FOLLOW_KEY + userId, followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        //查询
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count > 0);
    }

    @Override
    public Result followCommons(Long id) {
        //获取当前用户
        UserDTO userDTO = UserHolder.getUser();
        if (Objects.isNull(userDTO)) {
            return Result.fail("当前未登录");
        }
        String key = USER_FOLLOW_KEY + userDTO.getId();
        String key1 = USER_FOLLOW_KEY + id;
        //求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key1);
        //无交集
        if (intersect == null || intersect.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        //解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //查询用户
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(users);
    }
}
